> just because you trust that the pointer you give me is valid doesn't
> mean i trust you to give me a valid pointer, and if i keep the
> pointer for a few hours, will it still be valid?
> you can't say "yes", so i'm saying "no".
If a pointer might be invalid by the time you use it, merely checking
that it's a valid pointer is _not_ the right thing - it may now be a
valid pointer (once again, rather than still) but pointing to something
completely different.
Basically, I'm with Matt Thomas here.
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse@rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B